CONFIRMATORY FACTOR-ANALYSIS OF A 4-FACTOR MODEL OF CHRONIC PAIN EVALUATION

Extending the earlier work of Mikail et al. (1993), a confirmatory fac tor analysis (CFA; LISREL VII) of a 4-factor model of pain assessment was tested. This model, comprised of the Beck Depression Inventory (BD I) and 13 subscales of the McGill Pain Questionnaire (MPQ) and the Wes t Haven-Yale Multidimensional Pain Inventory (WHYMPI), adequately acco unted for the pain experience with minimal overlap. Subjects were 306 outpatient chronic pain patients seen at a multidisciplinary chronic p ain clinic. Subscale scores were subjected to CFA procedures that yiel ded a well-fitting final model that explained 91% of the covariance in the observed data. This final model was derived through an explorator y post-hoc procedure that allowed for correlated errors among subscale s of the same instrument. The 4 factors were identified as Affective D istress, Support, Pain Description, and Functional capacity. Results s upported the hypothesis that the MPQ, WHYMPI and BDI are representativ e of the multidimensionality of the pain experience with minimal overl ap among measures. Theoretical and clinical implications of reducing t he overlap among existing measures in the assessment of pain patients are discussed.